This invention relates to an electrophotographic printing machine, and more particularly concerns a trail edge copy registration system in a printing machine.
A typical electrophotographic printing machine utilized in the business office environment contains stacks of cut sheets of paper on which copies of original documents are reproduced. Generally, these cut sheets of paper are advanced through the printing machine, one sheet at a time, for suitable processing therein. Frequently, papers are advanced through the printing machine by transport subsystems. These subsystems are those sections of the paper handling module which drive copy paper from one printing processing station to another. Copy paper is directed to and from various subsystems by baffles and/or selection gates. All transports are directly driven from the main power drive and become operational upon "print command." The gates are usually solenoid operated and direct the copy paper as required to meet user selected output requirements. Attempts are made to design each transport where possible to allow ready accessibility to the copy paper by untrained machine operators. Coin switches are located throughout the various transports to provide jam protection.
One of the existing and standard methods for deskewing and side registering substrates in a copier includes the use of a ball-on-belt system. This system is used with a lead edge timing scheme and allows the lead edge of a substrate, driven by the belt, to be timed into a set of take away rolls so that the substrate reaches the transfer station in synchronism with a particular image on the photoreceptor. Some of the problems associated with this type of lead edge and side registration system encompasses mechanical drives for deskewing and shift registration and take away pinch roll drives.